1. Field of the Invention
The present invention relates to a pulsimeter sensor using magnetic thin films, and more particularly to a medical pulsimeter sensor, wherein a pulse-sensing part array consists of GMR (Giant Magneto Resistance) devices or MTJ (Magnetic Tunnel Junction) devices and the pulse-sensing part array is located over a skin-contacting part which consists of a magnetic material. When a radial pulse transferred to the magnetic material of the skin-contacting part results in changes in a magnetic field of the lower part of the pulse-sensing part array, and these changes in the magnetic field can be detected by the pulse-sensing part array. Finally, according to the present invention, the radial pulse can be measured noninvasively by detecting the changes of the magnetic field.
2. Description of the Related Art
Currently, most medical detecting sensors for the pulse are the invasive sensors, which detect the changes in the blood pressure by injecting tubes into the blood vessels, or the noninvasive sensors using pressure sensors.
Particularly, the pulsimeter sensor using pressure sensors has been researched many times due to its noninvasivity and the Korean Patent Publication Number 10-2001-0028665 regarding the medical pulsimeter sensor, the Korean Patent Publication Number 10-2002-96224 regarding the automatic pulsimeter, and the Korean Utility Registration Number 20-0358195 regarding the pulse wave measuring device et al. are some examples.
In the Korean Patent Publication Number 10-2001-28668, as shown in FIG. 1, the medical pulsimeter sensor includes a pressure-sensing sensor 4 including a silicon layer 1, which is adhered closely to the upper skin at the radial artery and close up the air layer tight to sense the pressure change of the air layer depending on the vibration of a pulse wave, a silicon gel 2, which transfers the pressure change of the air layer, and a pressure-measuring plate 3, which measures the pressure changes to be transferred by the silicon gel; a silicon gum 5, having a hole fit for the pressure-sensing part, wrapping the pressure-sensing part and being adhered to the front side of the pressure-sensing sensor 4 and making the pressure-sensing sensor 4 fixed to the skin of the examinee; and a fortified plastic plate 6, being adhered to the back side to the pressure-sensing sensor 4, and transferring the variable pressure from the back side of the pressure-sensing sensor 4 to the skin of the examinee.
The silicon layer 1 and the silicon gel 2, which are in front of the pressure-measuring plate 3, eliminate a cold feeling and unnecessary stimulus of metals, of which the conventional pulse-sensing part is comprised. However, the conventional pulsimeter sensor using pressure sensors has the problems that it unnecessarily closes up the air layer tight, transfers the pressure changes indirectly to a pressure-measuring plate and is unable to measure the exact pulse. And it is impossible to search for the location of the pulse depending on each person and measure an exact pulse quickly with the conventional pulsimeter sensor using pressure sensors.
By the way, Oriental medical doctors have diagnosed the three pulse locations on the wrist, over the radial artery classified as Chon, Gwan and Cheok. The “Gwan” is located on the coronal process of the radial artery on the wrist, the “Chon” is located on the spot 1˜1.3 cm from the Gwan toward a palm of the hand, and the “Cheok” is located on the spot 1˜1.3 cm from the Gwan toward an elbow. The doctor places the index, middle and ring fingers on the examinee's the Chon, Gwan and Cheok with three different degrees of pressing, that is, moderate (the “Bu” state), hard (the “Jung” state), and light (the “Chim” state).
To improve problems which the conventional pulsimeters have, the Korean Patent Publication Number 10-2002-96224 regarding the automatic pulsimeter, disclosed invention about mechanical embodiments of the way Oriental medical doctors feel the pulse with one pressure sensor and the Korean Utility Registration Number 20-0358195 regarding the pulse wave measuring device disclosed invention measuring the three regions of Chon, Gwan, and Cheok simultaneously with three pressure sensors.
However, the conventional arts use pressure sensors such as a piezoelectric device, and have the following problems:
First, it is possible to understand the time characteristics to some extent by measuring the changes in the pulse pressure (wave form) with the pressure sensors, but it is hard to understand the spatial characteristics (three-dimensional configurations) of the pulse such as the depth, the area, the length of the pulse and so on, which have been recognized more important in the traditional pulse diagnosis.
Accordingly, as shown in FIG. 2, only 7 qualities, those are related with the time characteristics, in words, slow pulse, rapid pulse, slippery pulse, uneven pulse, abrupt pulse, knotted pulse, and regularly intermittent pulse, can be understood by the conventional arts among 28 qualities that have been used in traditional pulse diagnosis. Therefore, there has been a limitation on replacing the traditional pulse diagnosis by examiners with these mechanical pulsimeters.
Second, products using the pressure sensors to understand the spatial characteristics of the pulse have been manufactured recently, but there is a limitation on the degree of integrity for pressure-sensors. Therefore, there is nothing but to get minimum spatial information about the pulse through an excess interpolation.
Third, to measure the spatial characteristics of the pulse properly, sensors should find out the location of the radial artery accurately. However, only several pressure sensors cannot search the center of the radial artery properly, and it takes too long to search the locations of the pulses.
Fourth, because of the nature of the pressure sensors of having a weakness in movement noises, it is impossible to measure pulses with wearing themselves, and this characteristic has an application limit to a portable apparatus.
Lastly, most pressure sensors have been equipped with measuring means of a rigid body, and an applying pressure on measurement of a pulse generates a pain.